iommu/iova: change IOVA_MAG_SIZE to 127 to save memory

mainline inclusion
from mainline-v5.19-rc5
commit b4c9bf17
bugzilla: https://gitee.com/openeuler/kernel/issues/I8KS9A
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b4c9bf178ace26c52c9cac36f265ba95132a221d



-------------------------------------------

kmalloc will round up the request size to power of 2, and current
iova_magazine's size is 1032 (1024+8) bytes, so each instance
allocated will get 2048 bytes from kmalloc, causing around 1KB
waste.

Change IOVA_MAG_SIZE from 128 to 127 to make size of 'iova_magazine'
1024 bytes so that no memory will be wasted.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20220703114450.15184-1-feng.tang@intel.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>